【作者】 刘勇；

【导师】 李会勇； 杨顺平；

【作者基本信息】 电子科技大学 ， 工程硕士（专业学位）， 2016， 硕士

【摘要】 现阶段,在天线测量领域,使用频率最高、适用范围最广的一种方法,即为近场测量技术,而作为该技术的一个分支,所谓球面近场测量指的是:通过采集包围被测天线虚拟最小球面上的近场数据,经过近远场变换程序能够得到完整的天线全方向图,是测试高性能天线的最有效方法。首先,介绍了基于单扫描不同权重设置的合成平面波传播在不同的方向,可以用来获得相关测试天线在不同方向的远场信息。在基于特征模式扩展的近场到远场转换方法中,近远场变换算法可以通过合成平面波的描述和算法验证来评价。在一个基于合成平面波场计算的验证过程中,可以很容易的研究探头校准的作用和对测量误差的影响。其次,球面近场测量技术对测量误差的影响可能很难直接评估,但可以通过应用计算机模拟仿真来实现。通过分析探头校准的影响和测量范围的截断效应,重点对其远场区域内的主波束和第一副瓣进行分析,将实际测量误差与仿真误差进行比较得出结论。接着,给出了基于等效电磁流模式的阵列天线近场诊断方法。通过球面近场测量数据与阵列天线的激励、单元方向图、探头方向图之间的联系,得到球面近场测量数据与阵列天线的激励之间的耦合方程。最后以标准喇叭天线为研究模型,使用Insight仿真软件,通过建立模型的方法对近场数据进行了求取,并借助变换程序的应用求得用于对比实测远场的远场数据。通过结果对比分析,得到一种新的基于远场方向图的近场诊断方法,并且对球面近场测量中存在的误差进行归纳分析。更多还原

【Abstract】 Near-field measurement technology is the most important means of antenna measurement at recently.Spherical near-field measurement is a kind of near-field measurement technique.By collecting the near-field data around the virtual minimum sphere of the measured antenna,the complete antenna pattern can be obtained through the near-far field transformation program,which is the most effective method.Firstly,the synthetic plane wave propagation in different directions based on single sweep weighting is introduced,which can be used to obtain the far field information of the relevant test antenna in different directions.In near-field to far-field conversion based on feature-mode expansion,the near-far field transform algorithm can be evaluated by synthetic plane wave description and algorithm verification.The effect of the probe calibration and the effect on the measurement error can be easily investigated in a verification process based on the synthetic plane wave field calculation.Secondly,the influence of the spherical near-field measurement technique on the measurement error may be difficult to be directly evaluated,but it can be realized by applying computer simulation.By analyzing the effects of probe calibration and the truncation effect of the measurement range,the main beam and the first side-lobe in the far-field region are analyzed,and the actual measurement error is compared with the simulation error to draw the conclusion.Then,a near-field diagnosis method of array antenna based on equivalent electromagnetic flow model is given.The coupling equations between spherical near-field measurement data and the excitation of the array antenna are obtained by the relationship between the spherical near-field measurement data and the excitation of the array antenna,the cell pattern and the probe pattern.Finally,the standard horn antenna is used as the research model.Near-field data are obtained by using Insight simulation software,and the far field is obtained by the near-far field transformation program,and compared with the measured far field.A new method of near-field diagnosis based on far-field pattern is obtained through the comparison of the results,and the errors existing in near-field measurement are analyzed.更多还原